|J. ashei shedding pollen: mature male on right, immature tree on left, mature green females in background|
|Natural range of Juniperus ashei|
Juniperus ashei (Ashe juniper, post cedar, mountain cedar, or blueberry juniper) is a drought-tolerant evergreen tree, native to northeastern Mexico and the south-central United States north to southern Missouri; the largest areas are in central Texas, where extensive stands occur. It grows up to 10 m (33 ft) tall, rarely 15 m (49 ft), and provides erosion control and year-round shade for wildlife and livestock.
A drought or drouth is a natural disaster of below-average precipitation in a given region, resulting in prolonged shortages in the water supply, whether atmospheric, surface water or ground water. A drought can last for months or years, or may be declared after as few as 15 days. It can have a substantial impact on the ecosystem and agriculture of the affected region and harm to the local economy. Annual dry seasons in the tropics significantly increase the chances of a drought developing and subsequent bush fires. Periods of heat can significantly worsen drought conditions by hastening evaporation of water vapour.
In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. Trees tend to be long-lived, some reaching several thousand years old. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees have been in existence for 370 million years. It is estimated that there are just over 3 trillion mature trees in the world.
Mexico, officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Covering almost 2,000,000 square kilometres (770,000 sq mi), the nation is the fifth largest country in the Americas by total area and the 13th largest independent state in the world. With an estimated population of over 120 million people, the country is the eleventh most populous state and the most populous Spanish-speaking state in the world, while being the second most populous nation in Latin America after Brazil. Mexico is a federation comprising 31 states and Mexico City, a special federal entity that is also the capital city and its most populous city. Other metropolises in the state include Guadalajara, Monterrey, Puebla, Toluca, Tijuana and León.
The feathery foliage grows in dense sprays, bright green in color. The leaves are scale-like, 2 to 5 mm (0.079 to 0.197 in) long, and produced on rounded (not flattened) shoots. It is a dioecious species, with separate male and female plants. The seed cones are round, 3 to 5 mm (0.12 to 0.20 in) long, and soft, pulpy and berry-like, green at first, maturing purple about 8 months after pollination. They contain one or two seeds, which are dispersed when birds eat the cones and pass the seeds in their droppings. The male cones are 3–5 mm long, yellow, turning brown after pollen release in December to February.
A cone is an organ on plants in the division Pinophyta (conifers) that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity. The name "cone" derives from the fact that the shape in some species resembles a geometric cone. The individual plates of a cone are known as scales.
In botany, a berry is a fleshy fruit without a stone produced from a single flower containing one ovary. Berries so defined include grapes, currants, and tomatoes, as well as cucumbers, eggplants (aubergines) and bananas, but exclude certain fruits commonly called berries, such as strawberries and raspberries. The berry is the most common type of fleshy fruit in which the entire outer layer of the ovary wall ripens into a potentially edible "pericarp". Berries may be formed from one or more carpels from the same flower. The seeds are usually embedded in the fleshy interior of the ovary, but there are some non-fleshy exceptions, such as peppers, with air rather than pulp around their seeds.
A seed is an embryonic plant enclosed in a protective outer covering . The formation of the seed is part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants.
The pollen causes a severe allergic reaction for some people in the winter, and people who are allergic to this juniper are also often allergic to the related Juniperus virginiana . Consequently, what begins as an allergy in the winter may extend into spring, since the pollination of J. virginiana follows that of J. ashei. Ashe juniper is sometimes known in the area as "mountain cedar" (although neither J. virginiana nor it are cedars), and locals usually refer to the allergy as cedar fever. Left untreated, symptoms of cedar fever may develop into a more severe infection such as pneumonia.
Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling. Food intolerances and food poisoning are separate conditions.
Juniperus virginiana, known as red cedar, eastern redcedar, Virginian juniper, eastern juniper, red juniper, pencil cedar, and aromatic cedar, is a species of juniper native to eastern North America from southeastern Canada to the Gulf of Mexico and east of the Great Plains. Further west it is replaced by the related Juniperus scopulorum and to the southwest by Juniperus ashei.
Cedrus is a genus of coniferous trees in the plant family Pinaceae. They are native to the mountains of the western Himalayas and the Mediterranean region, occurring at altitudes of 1,500–3,200 m in the Himalayas and 1,000–2,200 m in the Mediterranean.
The wood is naturally rot-resistant and provides raw material for fence posts. Posts cut from old-growth Ashe junipers have been known to last in the ground for more than 50 years. Over 100 years ago, most old-growth Ashe junipers were cut and used not only for fence posts, but also for telegraph poles and railroad ties.
When Europeans first came to the Hill Country, they sought out the cypress, post oaks, and native cedar (Ashe juniper), since they provided the best building materials. The first Spanish who came in the mid-1700s built Hill Country missions using the Ashe juniper for roof beams. As a result of poor land management, the soil turned to caliche as soil eroded following decades of clearcutting and overgrazing. One of the only plants that could handle the rocky soil was the Ashe juniper. Grasses could not establish on thin rocky soils on the more rolling to flat areas, so the junipers took over there, as well.
These days, Ashe Junipers are now considered a weed by many landowners. Some believe that it captures large amounts of water, denying it to other plants, thus causing them to die out and allowing the juniper to take over, although new evidence based on better research techniques conflicts with these claims.[ citation needed ]
Ranchers also consider it to be a pest plant because overgrazing by cattle selectively removes competition when they avoid the bitter-tasting juniper seedlings. This allows for a high rate of juniper establishment and reduces ranch yields. Ashe juniper does not resprout when cut, but the related redberry juniper does resprout.
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature reserves. It can also be caused by immobile, travel restricted populations of native or non-native wild animals. However, "overgrazing" is a controversial concept, based on equilibrium system theory.
Cattle—colloquially cows—are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos taurus.
Juniperus pinchotii is a species of juniper native to southwestern North America, in Mexico: Nuevo León and Coahuila, and in the United States: southeast New Mexico, central Texas, and western Oklahoma.
The junipers that establish on overgrazed lands are young and vigorous, dense and multitrunked, and shallow-rooted. This directly contrasts the Ashe junipers, which the first settlers found to be large, mostly single-trunk trees with some producing logs that were 2–3 ft in diameter and 40 ft long.
Where junipers do grow bushy on thinned, eroded soils, remaining grasses find competing for water difficult, especially if they are still being grazed and the soils are impoverished. The presence of these dense, shallow-rooted shrubs also means less water reaches the soil than areas with sparse, short grasses, subsurface flows, and deep drainage. However, their dense canopies and thick litter do reduce overland flows compared to grazed grasses. Also, much more water is evaporated from the sparse grass areas than originally calculated. Old-growth Ashe junipers are different in that they have true trunks, use less water, are slow growing and less foliated, and have very deep roots. These deeper roots may facilitate the deep drainage of water down trunk stemflows. For every inch of rain, about 6 gallons of previously undocumented water are funneled down the trunks.
Juniperus communis, the common juniper, is a species of conifer in the genus Juniperus, in the family Cupressaceae. It has the largest geographical range of any woody plant, with a circumpolar distribution throughout the cool temperate Northern Hemisphere from the Arctic south in mountains to around 30°N latitude in North America, Europe and Asia. Relict populations can be found in the Atlas Mountains of Africa.
Juniperus oxycedrus, vernacularly called Cade, cade juniper, prickly juniper, prickly cedar, or sharp cedar, is a species of juniper, native across the Mediterranean region from Morocco and Portugal, north to southern France, east to westernmost Iran, and south to Lebanon and Israel, growing on a variety of rocky sites from sea level up to 1600 m elevation. The specific epithet oxycedrus means "sharp cedar" and this species may have been the original cedar or cedrus of the ancient Greeks.
Juniperus osteosperma is a shrub or small tree reaching 3–6 m tall. It is native to the southwestern United States, in Utah, Nevada, Arizona, western New Mexico, western Colorado, Wyoming, southern Montana, southern Idaho and eastern California. It grows at moderate altitudes of 1,300–2,600 metres (4,300–8,500 ft), on dry soils, often together with Pinus monophylla.
Juniperus drupacea, the Syrian juniper, is a species of juniper native to the eastern Mediterranean region from southern Greece, southern Turkey, western Syria, and Lebanon, growing on rocky sites from 800–1700 m altitude.
Juniperus californica, the California juniper, is a species of juniper native to southwestern North America.
Juniperus occidentalis is a shrub or tree native to the western United States, growing in mountains at altitudes of 800–3,000 metres (2,600–9,800 ft) and rarely down to 100 metres (330 ft).
Juniperus scopulorum, the Rocky Mountain juniper, is a species of juniper native to western North America, in Canada in British Columbia and southwest Alberta, in the United States from Washington east to North Dakota, south to Arizona and also locally western Texas, and northernmost Mexico from Sonora east to Coahuila. It grows at altitudes of 500–2,700 metres (1,600–8,900 ft) on dry soils, often together with other juniper species. "Scopulorum" means "of the mountains.
Juniperus horizontalis is a low-growing shrubby juniper native to northern North America, throughout most of Canada from Yukon east to Newfoundland, and in the United States in Alaska, and locally from Montana east to Maine, reaching its furthest south in Wyoming and northern Illinois.
Juniperus deppeana is a small to medium-sized tree reaching 10–15 m tall. It is native to central and northern Mexico and the southwestern United States. It grows at moderate altitudes of 750–2,700 meters (2,460–8,860 ft) on dry soils.
Juniperus phoenicea, the Phoenicean juniper or Arâr, is a juniper found throughout the Mediterranean region, from Morocco and Portugal east to Italy, Turkey and Egypt, south on the mountains of Lebanon, the Palestine region and in western Saudi Arabia near the Red Sea, and also on Madeira and the Canary Islands. It mostly grows at low altitudes close to the coast, but reaches 2,400 metres (7,900 ft) altitude in the south of its range in the Atlas Mountains. It is the vegetable symbol of the island of El Hierro.
Juniperus coahuilensis, commonly known as redberry juniper, is a species of conifer in the family Cupressaceae.
Juniperus monosperma is a species of juniper native to western North America, in the United States in Arizona, New Mexico, southern Colorado, western Oklahoma (Panhandle), and western Texas, and in Mexico in the extreme north of Chihuahua. It grows at 970–2300 m altitude.
Juniperus semiglobosa is a species of juniper native to the mountains of Central Asia, in northeastern Afghanistan, westernmost China (Xinjiang), northern Pakistan, southeastern Kazakhstan, Kyrgyzstan, western Nepal, northern Republic of India, Tajikistan, and Uzbekistan. It grows at altitudes of 1,550–4,350 metres (5,090–14,270 ft) .
Juniperus tibetica is a species of juniper, native to western China in southern Gansu, southeastern Qinghai, Sichuan, and Tibet, where it grows at high to very high altitudes of 2,600–4,800 metres (8,500–15,700 ft). This species may possess the highest elevation treeline in the world.
Callophrys gryneus, the juniper hairstreak or olive hairstreak, is a butterfly native to North America. It belongs in the family Lycaenidae.
Phomopsisblight of juniper is a foliar disease discovered in 1917 caused by the fungal pathogen Phomopsis juniperovora. The fungus infects new growth of juniper trees or shrubs, i.e. the seedlings or young shoots of mature trees. Infection begins with the germination of asexual conidia, borne from pycnidia, on susceptible tissue, the mycelia gradually move inwards down the branch, and into the main stem. Management strategies mainly include removing and destroying diseased tissue and limiting the presence of moisture on plants. Junipers become resistant to infection as they mature and the young yellow shoots turn dark green. Preventative strategies include planting only resistant varieties and spraying new growth with fungicide until plants have matured.
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